Blends of linear low density polyethylenes

ABSTRACT

A polyethylene blend comprising a uniform dispersion of constituents (A) and (B): (A) a Ziegler-Natta catalyst-made linear low density polyethylene and (B) a metallocene catalyst-made linear low density polyethylene, a composition comprising the polyethylene blend and at least one additive, methods of making and using same, and manufactured articles and films comprising or made from same.

FIELD

The field includes linear low density polyethylene blends andcompositions containing same, methods of making and using same, andmanufactured articles and films.

INTRODUCTION

A linear low density polyethylene (“LLDPE”) is a substantially linearmacromolecule composed of ethylene monomeric units and alpha-olefincomonomeric units. The typical comonomeric units used in commerce arederived from 1-butene, 1-hexene, or 1-octene. A LLDPE may bedistinguished from a conventional low density polyethylene (“LDPE”) anynumber of ways. Their respective manufacturing processes are different.LLDPE has substantially no detectable long chain branching per 1,000carbon atoms, whereas conventional LDPE contains long chain branching.LLDPE has a narrower molecular weight distribution (MWD) relative to MWDof LDPE. LLDPE has different respective optical properties such asclarity (Zebedee), gloss, and haze.

US 2014/0179873 A1 to P. Lam, et al. (LAM) relates to a polymer blendcomprising first and second polyethylene copolymers. The blend may bemade into a film.

KR 2016062727A and KR2014002351A relate to polyethylenes and films.

SUMMARY

We recognized a problem that hurts the manufacturing and performance ofprior LLDPE films. The films may have deficient film optical propertiessuch as clarity, gloss, or haze.

A technical solution to this problem was not obvious. Many past attemptsto improve (increase) optical properties of polyethylene films failed. Aproblem to be solved then is to discover an LLDPE film that has animproved film optical property.

Our technical solution to this problem includes a polyethylene blend(inventive blend) comprising a uniform dispersion of constituents (A)and (B): (A) a Ziegler-Natta catalyst-made linear low densitypolyethylene (ZN-LLDPE) and (B) a metallocene catalyst-made linear lowdensity polyethylene (MCN-LLDPE). We discovered that when the ZN-LLDPEhas a first combination of properties and the MCN-LLDPE has a secondcombination of properties, and the ZN-LLDPE and MCN-LLDPE are uniformlymixed together in certain relative amounts, the result is a blend thathas at least one enhanced optical property such as enhanced (increased)clarity, enhanced (increased) gloss, and/or enhanced (decreased) haze,all relative to the respective optical property that would be expectedfor the blend based on films composed of the ZN-LLDPE alone or theMCN-LLDPE alone. Also inventive are a polyethylene compositioncomprising the inventive blend and at least one additive that is not (A)or (B) (inventive composition), a method of making the blend, a methodof shaping the blend into an article, and a manufactured articlecomposed of or made from the blend or composition.

DETAILED DESCRIPTION

The Summary and Abstract are incorporated here by reference.

The “enhanced optical property” for the inventive blend is describedrelative to the optical property of a first comparative film composed ofthe (A) ZN-LLDPE alone (100 wt % ZN-LLDPE/0 wt % MCN-LLDPE film) andoptical property of a second comparative film composed of the (B)MCN-LLDPE alone (0 wt % ZN-LLDPE/100 wt % MCN-LLDPE film). Measureoptical properties of comparative and inventive films according to ASTMD1746-15 for clarity (Zebedee), ASTM D2457-13 for gloss (specular), andASTM D1003-13 for haze. Express optical property values for clarity(Zebedee), the measure of light that is scattered less than 1 degree (°)from the axis of incident light, as the ratio of light intensity withspecimen to without specimen in the path of light as percenttransmittance. Specular gloss is used primarily as a measure of theshiny appearance of films and surfaces at particular angle (e.g., 45°).Haze is expressed in percentage of luminous transmission which inpassing through the film deviates from an incident beam by forwardscattering. For comparison, use a film having a thickness of 0.0127millimeter (mm, 0.500 mil) thick film. Alternatively films of otherthickness may be compared, such as 0.0254 mm (1.00 mil), 0.0381 mm (1.50mil), 0.0508 mm (2.00 mils), or 0.0635 mm (2.50 mils). Plot the opticalproperty values for the first and second comparative films on a y-axisversus their respective weight fraction concentrations on an x-axis.Draw a comparative trend line (straight) from the optical property valuefor the first comparative film (100 wt % ZN-LLDPE/0 wt % MCN-LLDPE) tothe optical property value for the second comparative film (0 wt %ZN-LLDPE/100 wt % MCN-LLDPE). Then plot the optical property value foreach of the blends of (A) ZN-LLDPE and (B) MCN-LLDPE. Absence anyenhancement, the optical property values for the blends (e.g., 75 wt %ZN-LLDPE/25 wt % MCN-LLDPE, 50 wt % ZN-LLDPE/50 wt % MCN-LLDPE, and 25wt % ZN-LLDPE/75 wt % MCN-LLDPE) would be expected to fall on thecomparative trend line.

Unpredictably, however, at least one optical property value for theinventive blend is above the comparative trend line. Thus, the inventiveblend has at least one enhanced optical property. The extent ofenhancement, indicated by the distance above the comparative trend line,may be expressed as an absolute optical property value, alternatively bya percentage increase above the comparative trend line. If an opticalproperty value for any particular embodiment of a polyethylene blendlies on or below its comparative trend line, that particular embodimentis not included herein.

In some aspects the inventive blend embodiments fall within a weightfraction concentration range wherein the (A) ZN-LLDPE is from 15 to 75weight percent (wt %) of the total weight of (A) and (B) and the (B)MCN-LLDPE is from 85 to 25 wt % of the total weight of (A) and (B).Embodiments of the inventive blend are not restricted to those weightfraction concentration ranges, however, provided that they arecharacterized by at least one optical property value that is above theirrespective comparative trend lines.

Certain inventive embodiments are described below as numbered aspectsfor easy cross-referencing. Additional embodiments are described herein.

Aspect 1. A polyethylene blend comprising a uniform dispersion ofconstituents (A) and (B): (A) a Ziegler-Natta catalyst-made linear lowdensity polyethylene (ZN-LLDPE) and (B) a metallocene catalyst-madelinear low density polyethylene (MCN-LLDPE); wherein the (A) ZN-LLDPE isfrom 11 to 79 weight percent (wt %) of the total weight of (A) and (B)and the (B) MCN-LLDPE is from 89 to 21 wt % of the total weight of (A)and (B); wherein by itself (A) is independently characterized byproperties (i) to (iii): (i) a melt index (“I₂”, 190° C., 2.16 kg) of0.5 to 2.5 gram per 10 minutes (g/10 min.) measured according to ASTMD1238-04; (ii) a density from 0.905 to 0.930 gram per cubic centimeter(g/cm³), measured according to ASTM D792-13; and (iii) no detectableamount of long chain branching per 1,000 carbon atoms (“LCB Index”),measured according to LCB Test Method (described later); and wherein byitself (B) is independently characterized by properties (i) to (iii):(i) a melt index (“I₂”, 190° C., 2.16 kg) of 0.5 to 2.5 g/10 min.measured according to ASTM D1238-04; (ii) a density from 0.905 to 0.930g/cm³, measured according to ASTM D792-13; and (iii) no detectableamount of long chain branching per 1,000 carbon atoms (“LCB Index”),measured according to LCB Test Method (described later); and with theproviso that the density of constituent (B) is within ±0.003 g/cm³,alternatively ±0.002 g/cm³, alternatively ±0.001 g/cm³ of the density ofconstituent (A).

Aspect 2. The polyolefin blend of aspect 1, further characterized by oneof limitations (i) to (vii): (i) each of ZN-LLDPE and MCN-LLDPE isindependently characterized by a melt index of (“I₂”, 190° C., 2.16 kg)of 0.5 to 1.99 g/10 min.; (ii) the melt index of constituent (B) iswithin ±0.4 g/10 min. of the melt index of constituent (A); (iii) both(i) and (ii); (iv) each of the ZN-LLDPE and MCN-LLDPE is independentlycharacterized by a density of 0.918±0.003 g/cm³; (v) the density ofconstituent (B) is within ±0.001 g/cm³ of the density of constituent(A); (vi) both (iv) and (v); or (vii) both (iii) and (vi).

Aspect 3. The polyolefin blend of aspect 1 or 2, when formed as a filmhaving a thickness of 0.0127 millimeter (0.500 mil), is furthercharacterized by any one of limitations (i) to (vii): (i) an improvement(increase) in optical clarity (Zebedee), relative to optical clarity(Zebedee) of a film of (A) alone or (B) alone, of 3% to 35%,alternatively from 6% to 23%, alternatively from 3% to 31%,alternatively from 18% to 20%, all when tested according to the OpticalClarity-Zebedee Test Method described later; (ii) an improvement(increase) in gloss of from 15% to 65%, alternatively 49% to 57%,alternatively 33% to 59%, alternatively 27% to 64%, all when testedaccording to the Optical Gloss Test Method described later; (iii) animprovement (decrease) in haze of from 15% to 65%, alternatively 39% to61%, alternatively 29% to 61%, alternatively 19% to 47%, all when testedaccording to the Optical Haze Test Method described later; or (iv) both(i) and (ii); (v) both (i) and (iii); (vi) both (ii) and (iii); or (vii)each of (i) to (iii). The improved optical property may be enhanced(increased) clarity, enhanced (increased) gloss, and/or enhanced(decreased) haze.

Aspect 4. A method of making the polyolefin blend of any one of aspects1 to 3, the method comprising: (a) contacting discrete solid particlesand/or a discrete melt of constituent (A) with discrete solid particlesand/or a discrete melt of constituent (B) to give an initial mixture of(A) and (B); (b) heating any solid particles of (A) and any solidparticles of (B) in the initial mixture above their melting temperatureto give a complete melt of constituents (A) and (B); (c) blending thecomplete melt to an even extent to give the polyolefin blend as auniform melt blend of constant composition of (A) and (B) throughout. Ifthe initial mixture does not contain any solid particles of (A) and/or(B), then step (b) is unnecessary and may be omitted if desired. Theexpression “discrete solid particles and/or a discrete melt” meansdiscrete solid particles, a discrete melt, or a combination thereof.E.g., see Blend and Film Preparation Method 1 later.

Aspect 5. The method of aspect 4, further comprising (d) cooling theuniform melt blend to a temperature below its solidificationtemperature, thereby giving the polyolefin blend as a solid of constantcomposition of (A) and (B) throughout.

Aspect 6. A polyolefin composition comprising the polyolefin blend ofany one of aspects 1 to 3, or the polyolefin blend made by the method ofaspect 4 or 5, and at least one additive (constituent) (C) to (M): (C) alubricant; (D) a polymer processing aid; (E) an antioxidant; (F) a metaldeactivator; (G) an ultraviolet light-promoted degradation inhibitor(“UV stabilizer”); (H) a slip agent; (I) a hindered amine stabilizer;(J) an antiblock agent; (K) a colorant; (L) an antifog agent; and (M) anantistatic agent; with the proviso that the total amount of the at leastone additive is from >0 to 5 wt % of the polyolefin composition and thepolyolefin blend is from <100 to 80 wt % of the polyolefin composition.

Aspect 7. A method of making the polyolefin composition of aspect 6, themethod comprising contacting the polyolefin blend with the at least oneadditive (C) to (M) to give the polyolefin composition.

Aspect 8. A manufactured article comprising a shaped form of thepolyolefin blend of any one of aspects 1 to 3, the polyolefin blend madeby the method of aspect 4 or 5, or the polyolefin composition of aspect6.

Aspect 9. A polyethylene film of the polyolefin blend of any one ofaspects 1 to 3 or the polyolefin blend made by the method of aspect 4 or5.

Aspect 10. A method of making a polyethylene film, the method comprisingrestricting in one dimension the polyethylene blend of any one ofaspects 1 to 3 or the polyethylene blend made by the method of aspect 4or 5 or the polyolefin composition of aspect 6, thereby giving thepolyethylene film. E.g., see Blend and Film Preparation Method 1 later.

All properties described herein are measured according to theirrespective standard test methods described later unless explicitlyindicated otherwise. Density is measured according to ASTM D792-13. Meltindex (I₂) is measured according to ASTM D1238-04 (190° C., 2.16 kg).

Polyolefin blend. The polyolefin blend comprises a uniform dispersion ofconstituents (A) and (B). The term “uniform dispersion” refers to theconstituents (A) and (B) as being mixed or blended together to an evenextent, such that the resulting material is of constant composition of(A) and (B) throughout. The uniform dispersion of (A) and (B) may beliquid (melt) or a solid. The uniform dispersion may further contain aproduct of a reaction of some of (A) with some of (B) so as to formproduct (A)-(B).

In the polyolefin blend, the relative amount of (A) may be in the rangeof from 16 to 79 wt % and (B) in the range from 84 to 21 wt %,alternatively (A) may be in the range of from 24 to 76 wt % and (B) inthe range from 76 to 24 wt %, alternatively (A) may be in the range offrom 24 to 55 wt % and (B) in the range from 76 to 45 wt %; all based ontotal weight of (A) and (B).

In the polyolefin blend, the uniform dispersion of (A) and (B) ischaracterized by its own properties, which are different than suchproperties of (A) or (B) alone, or of a mixture of discrete particles of(A) and discrete particles of (B), such as a blend of pellets of (A) andpellets of (B). The inventive blend may include at least one enhancedproperty, relative to that of (A) or (B) alone, that includes the atleast one enhanced optical property. An optional additional enhancementmay include enhanced (increased) puncture resistance. An optionaladditional enhancement may include tear strength and/or tensile yieldstrength. Optionally the enhanced at least one property further mayinclude dart impact and/or modulus.

In some aspects the polyolefin blend is independently furthercharacterized by one of limitations (iv) to (vi): (iv) a normalcomonomer distribution measured according to Gel PermeationChromatography (GPC) Test Method (described later).

As an alternative or addition to the foregoing properties, thepolyolefin blend may be characterized by its chemical composition,chemical composition distribution (CCD), density, melt viscosity (η),melt index (I₂, 190° C., 2.16 kg), melting transition temperature(s),molecular weight distribution (MWD=M_(w)/M_(n)), number averagemolecular weight (M_(n)), weight average molecular weight (M_(w)), or acombination of any two or more thereof.

The polyolefin blend may have an atomic chemical composition thatconsists essentially of, alternatively consists of C, H, and remaindersof the Ziegler-Natta and metallocene catalysts. The atomic chemicalcomposition of the Ziegler-Natta catalyst remainder may consistessentially of, alternatively consist of Ti, Mg, and Cl. The atomicchemical composition of the metallocene catalyst remainder may consistessentially of, alternatively consist of a Group 4 metal (e.g., Ti, Zr,or Hf), C, H, and, optionally, Cl, O, and/or N.

The polyolefin blend may have a density from 0.915 to 0.926 g/cm³,alternatively 0.920 to 0.926 g/cm³, alternatively 0.918±0.003 g/cm³,alternatively 0.918±0.002 g/cm³, alternatively 0.918±0.001 g/cm³,alternatively 0.918 g/cm³, all measured according to ASTM D792-13.

The polyolefin blend may have a melt index I₂ from 0.5 to 2.04 g/10min., alternatively from 0.5 to 1.99 g/10 min., alternatively from 0.6to 1.4 g/10 min., alternatively from 0.9 to 1.1 g/10 min., all measuredaccording to ASTM D1238-04. The melt index of constituent (B) may bewithin ±0.3 g/10 min., alternatively within ±0.2 g/10 min.,alternatively within ±0.1 g/10 min., of the melt index of constituent(A).

The polyolefin blend may have no detectable amount of long chainbranching per 1,000 carbon atoms (“LOB Index”), measured according toLOB Test Method (described later). The polyolefin blend may becharacterized by at least one optical property described later.

The polyolefin blend may be characterized by at least one of properties(ii) to (iii): (ii) tear strength (MD or CD) from 10 to 1,000 grams per25 micrometers (g/25 μm), alternatively 20 to 900 g/25 μm, alternatively50 to 500 g/25 μm, and (iii) tensile yield strength (MD or CD) from 5 to15 megapascals (MPa), alternatively 6 to 14 MPa, alternatively 7 to 13MPa. The properties may also include dart impact from 0 to 2,000 grams(g), alternatively 1 to 1,500 g, alternatively 5 to 1,000 g and/ormodulus from 100 to 400 MPa.

Alternatively or additionally, the polyolefin blend may be characterizedby characteristics of constituent (A), constituent (B), or both (A) and(B) prior to being blended. Prior to blending, each of (A) and (B)independently may be characterized by its chemical composition, CCD,density, melt viscosity (η), melt index (I₂, 190° C., 2.16 kg), meltingtransition temperature, MWD (M_(w)/M_(n)), M_(n), M_(w), or acombination of any two or more thereof. The constituents (A) and (B) ofthe polyolefin blend are composed of macromolecules. The macromoleculesof (A), (B), or both (A) and (B) independently may consist of carbon andhydrogen atoms. As such the macromolecules (A) and/or (B) independentlymay be free of other heteroatoms (e.g., halogen, N, O, S, Si, and P). Insome aspects (A) and (B) are independently characterized by their meltindexes (I₂, 190° C., 2.16 kg) and densities described later. Forexample, in some aspects (A) has a melt index (I₂, 190° C., 2.16 kg)from 0.5 to 1.99 g/10 min. and (B) has a melt index (I₂, 190° C., 2.16kg) from 0.5 to 2.04 g/10 min.; alternatively (B) has a melt index (I₂,190° C., 2.16 kg) from 0.5 to 1.99 g/10 min. and (A) has a melt index(I₂, 190° C., 2.16 kg) from 0.5 to 2.04 g/10 min.; alternatively both(A) and (B) each have a melt index (I₂, 190° C., 2.16 kg) from 0.5 to1.99 g/10 min.

Constituent (A): Ziegler-Natta catalyst-made linear low densitypolyethylene (ZN-LLDPE). The ZN-LLDPE is manufactured by copolymerizingethylene and an alpha-olefin comonomer in the presence of aZiegler-Natta catalyst such as TiCl₄ disposed on a particulate MgCl₂support. Ziegler-Natta catalysts are well known and include theZiegler-Natta catalyst components and systems at column 12, lines 13 to49; column 12, line 58, to column 13, line 25; and the cocatalysts atcolumn 13, line 31 to column 14, line 28, of U.S. Pat. No. 7,122,607 B2to Robert O. Hagerty, et al. The copolymerization process is generallywell known and may be a slurry phase, solution phase, or gas phaseprocess. For example a suitable gas phase process is at column 25, line59, to column 26, line 21, and column 33, line 32, to column 35, line56, of U.S. Pat. No. 7,122,607 B2.

The alpha-olefin comonomer used to make (A) may be a(C₃-C₂₀)alpha-olefin, alternatively a (C₁₁-C₂₀)alpha-olefin,alternatively a (C₃ to C₁₀)alpha-olefin, alternatively a(C₄-C₈)alpha-olefin, alternatively 1-butene or 1-hexene, alternatively1-butene, alternatively 1-hexene, alternatively 1-octene. (A) may becharacterized by its monomer content (i.e., ethylene monomeric content)and comonomer content (i.e., alpha-olefin comonomeric content). Thealpha-olefin comonomeric units of (A) may be 1-butene comonomeric units,alternatively 1-hexene comonomeric units, alternatively 1-octenecomonomeric units.

(A) may have a density from 0.905 to 0.930 g/cm³, alternatively 0.915 to0.926 g/cm³, alternatively 0.920 to 0.926 g/cm³, alternatively0.918±0.003 g/cm³, alternatively 0.918±0.002 g/cm³, alternatively0.918±0.001 g/cm³, alternatively 0.918 g/cm³, all measured according toASTM D792-13. (A) may have a melt index I₂ from 0.5 to 2.5 g/10 min.,alternatively from 0.5 to 2.04 g/10 min., alternatively from 0.5 to 1.99g/10 min., alternatively from 0.6 to 1.4 g/10 min., alternatively from0.9 to 1.1 g/10 min., all measured according to ASTM D1238-04. (A) mayhave M_(w) from 1,000 to 1,000,000 grams per mole (g/mol), alternativelyfrom 10,000 to 500,000 g/mol, alternatively from 20,000 to 200,000g/mol. (B) may have MWD (M_(w)/M_(n)) from 3.0 to 25, alternatively from4 to 20, alternatively from 5 to 10.

Examples of (A) are commercially available and include DOW LLDPE DFDA7047NT 7; Formosa Plastics FORMOLENE L42022B; Westlake ChemicalCorporation's HIFOR LF1021 and NOVAPOL TD-9022; and Chevron Phillips'MARFLEX 7109 Polyethylene.

Constituent (B): metallocene catalyst-made linear low densitypolyethylene (MCN-LLDPE). The MCN-LLDPE is manufactured bycopolymerizing ethylene and an alpha-olefin comonomer in the presence ofa metallocene catalyst such as zirconocene. Metallocene catalysts arewell known and include the metallocene catalyst components and systemsat column 14, line 30, to column 20, line 67; and the activators andactivator methods at column 21, line 1 to column 25, line 57, of U.S.Pat. No. 7,122,607 B2. The copolymerization process is generally wellknown and may be a slurry phase, solution phase, or gas phase process.For example a suitable gas phase process is at column 25, line 59, tocolumn 26, line 21, and column 33, line 32, to column 35, line 56, ofU.S. Pat. No. 7,122,607 B2.

The alpha-olefin comonomer used to make (B) may be a(C₃-C₂₀)alpha-olefin, alternatively a (C₁₁-C₂₀)alpha-olefin,alternatively a (C₃ to C₁₀)alpha-olefin, alternatively a(C₄-C₈)alpha-olefin, alternatively 1-butene or 1-hexene, alternatively1-butene, alternatively 1-hexene, alternatively 1-octene. (B) may becharacterized by its monomer content (i.e., ethylene monomeric content)and comonomer content (i.e., alpha-olefin comonomeric content). Thealpha-olefin comonomeric units of (B) may be 1-butene comonomeric units,alternatively 1-hexene comonomeric units, alternatively 1-octenecomonomeric units. The alpha-olefin comonomer used to make (B) may thesame as, alternatively is different than the alpha-olefin used to make(A).

(B) may be characterized by the molecular catalyst used to make it. Themolecular catalyst may be a metallocene, alternatively a zirconocene,alternatively a constrained geometry catalyst.

(B) may have a density from 0.905 to 0.930 g/cm³, alternatively 0.915 to0.926 g/cm³, alternatively 0.920 to 0.926 g/cm³, alternatively0.918±0.003 g/cm³, alternatively 0.918±0.002 g/cm³, alternatively0.918±0.001 g/cm³, alternatively 0.918 g/cm³, all measured according toASTM D792-13. (B) may have a melt index I₂ from 0.5 to 2.5 g/10 min.,alternatively from 0.5 to 2.04 g/10 min., alternatively from 0.5 to 1.99g/10 min., alternatively from 0.6 to 1.4 g/10 min., alternatively from0.9 to 1.1 g/10 min., all measured according to ASTM D1238-04. (B) mayhave M_(w) from 1,000 to 1,000,000 g/mol, alternatively from 10,000 to500,000 g/mol, alternatively from 20,000 to 200,000 g/mol. (B) may haveMWD (M_(w)/M_(n)) from >2.00 to 3.0, alternatively from 2.01 to 2.9,alternatively from 2.1 to 2.5.

Examples of (B) are commercially available and include ExxonMobil EXCEED1018HA, Ineos ELTEX PF6012AA; Chevron Phillips' MARFLEX D170DkPolyethylene; Sabic's SUPEER 8118(L) mLLDPE; and TOTAL's PolyethyleneLUMICENE M 1810 EP.

Polyolefin composition. The polyolefin composition comprises thepolyolefin blend and the at least one additive, such as additive (C) to(M) described earlier. The inventive composition independently may,alternatively may not have a constant composition of the inventive blendand/or the at least one additive throughout. In some aspects thepolyolefin composition comprises at least one of the (C) lubricant.Suitable lubricants are carbowax and metal stearates, (D) polymerprocessing aid (e.g., Dunamar FX), (E) antioxidant such as a primaryantioxidant or a combination of primary and secondary antioxidants, (F)metal deactivator, (G) UV stabilizer (e.g., silica or carbon black), and(H) slip agent, (I) hindered amine stabilizer, (J) antiblock agent, (K)colorant, (L) antifog agent, and (M) antistatic agent. A suitable amountof each of the additives may be from >0 to 5 weight percent (wt %),alternatively 0.5 to 5 wt %, alternatively 1 to 2 wt %. The total weightof all constituents, including additives, in the polyolefin compositionis 100.00 wt %.

The polyolefin blend and polyolefin composition may be substantiallyfree of, alternatively may not contain, a polyolefin other thanconstituents (A) and (B). E.g., may be substantially free from or,alternatively does not contain, a conventional low density polyethylene(LDPE), a medium density polyethylene (MDPE), a high densitypolyethylene (HDPE), a poly(alpha-olefin), an ethylene/unsaturatedcarboxylic ester copolymer, a polyorganosiloxane, a poly(alkyleneglycol), or a polystyrene.

The polyolefin composition may be made by any suitable method providedthat (A) and (B) are blended together to give the polyolefin blend. The(A) and (B) may be blended together as described herein before beingcontacted with any additive. That is, the polyolefin blend containingthe uniform mixture of (A) and (B) may be made, and then later theuniform mixture may be contacted with any optional additive (C) to (L)or constituent. Alternatively, the (A) and (B) may be blended togetheras described herein in the presence of one or more optional additives(C) to (L), if any, to give an embodiment of the polyolefin blendfurther containing the one or more additives. Typically for (C), thepolyolefin blend is made, and then the (C) organic peroxide is added tothe polyolefin blend to give the polyolefin composition.

To facilitate mixing of a preformed polyolefin blend of constituents (A)and (B) with the additive(s), the additive(s) may be provided in theform of an additive masterbatch, i.e., a dispersion of additive(s) in acarrier resin. Before making the preformed polyolefin blend, some of (A)or (B), or afterwards some of the preformed polyolefin blend of (A) and(B), may be set aside for use as the carrier resin.

Method of making the polyethylene blend. “Discrete solid particlesand/or a discrete melt” means discrete solid particles, a discrete melt,or a combination thereof. In some aspects step (a) comprises dryblending discrete solid particles consisting essentially of,alternatively consisting of (A) with discrete solid particles consistingessentially of, alternatively consisting of (B) to give an aspect of theinitial mixture consisting essentially of, alternatively consisting ofsolid particles of (A) and solid particles of (B). As used above“consisting essentially of” means one or more additives (C) to (L) maybe present, but other polyolefins are absent. In some aspects step (a)comprises melt blending a melt consisting essentially of, alternativelyconsisting of (A) with a melt consisting essentially of, alternativelyconsisting of (B) to give an aspect of the initial mixture consistingessentially of, alternatively consisting of a melt of (A) and a melt of(B). In some aspects step (a) is a combination of both of the foregoingaspects. The amount of (A) and the amount of (B) used in the method maybe measured and selected so as to give an aspect of the polyethyleneblend having a specific wt % of (A) in the range of from 15 to 75 wt %and a specific wt % of (B) in the range from 85 to 25 wt %, based ontotal weight of (A) and (B), or each in any one of the alternativeranges thereof described earlier.

In the method of making the polyethylene blend, in some aspects step (b)comprises heating an aspect of the initial mixture of step (a)containing solid particles of (A) having a first melting temperatureand/or heating solid particles of (B) having a second meltingtemperature above the highest one of the first and second meltingtemperatures to give the complete melt of (A) and (B). The aspect of theinitial mixture may also contain, alternatively may not contain apartial melt of (A) and/or a partial melt of (B). In some aspects step(b) heating is performed in an extruder such as a single screw or twinscrew extruder configured with a heating device.

In some aspects step (b) of the method of making the polyethylene blendis unnecessary if step (a) comprises the melt blending a melt consistingessentially of, alternatively consisting of (A) with a melt consistingessentially of, alternatively consisting of (B) to give an aspect of theinitial mixture consisting essentially of, alternatively consisting of amelt of (A) and a melt of (B). In the latter aspects the initial mixtureof step (a) is free of solid particles of (A) and (B).

In the method of making the polyethylene blend, in some aspects step (c)comprises using the extruder (e.g., the single screw or twin screwextruder) to blend the complete melt of step (b) to an even extent togive the polyolefin blend as a uniform melt blend of constantcomposition of (A) and (B) throughout.

In the method of making the polyethylene blend, in some aspects step (d)comprises passive cooling (natural cooling without using energy),alternatively active cooling (using energy to remove heat) of theuniform melt blend to a temperature below its solidificationtemperature, thereby giving the polyolefin blend as a solid uniformdispersion of constant composition of (A) and (B) throughout. Thecooling may be performed at a controlled rate during the temperaturerange in which the polyethylene blend or its constituents (A) and (B)solidify, thereby controlling the morphology of the solidifiedpolyethylene blend.

The polyethylene film. In some aspects the polyethylene film has athickness from 0.0102 to 0.254 mm (0.400 mil to 10 mils), alternativelyfrom 0.01143 mm to 0.254 mm (0.450 mil to 10 mils), alternatively from0.01143 mm to 0.127 mm (0.450 mil to 5.00 mils), alternatively from0.01143 mm to 0.0762 mm (0.450 mil to 3.00 mils), alternatively from0.0127 mm to 0.0635 mm (0.500 mil to 2.50 mils). In some aspects thepolyethylene film is made as an aspect of the method of making thepolyethylene blend or composition. In such aspects the polyethylene filmmay be made after step (c) blending and before step (d) cooling, both ofthe method of making the polyethylene blend or composition. In some suchaspects the polyethylene film is made by a method that comprises: (a)dry blending discrete solid particles consisting essentially of,alternatively consisting of (A) with discrete solid particles consistingessentially of, alternatively consisting of (B) to give an aspect of theinitial mixture consisting essentially of, alternatively consisting ofsolid particles of (A) and solid particles of (B); (b) heating theinitial mixture to give the complete melt of constituents (A) and (B);(c) blending the complete melt to an even extent to give the polyolefinblend as a uniform melt blend of constant composition of (A) and (B)throughout; (d) blowing the uniform melt blend so as to form a film andcool same to give the polyolefin blend as a polyethylene film aspect ofthe manufactured article.

The polyethylene film may be made using any blown-film-line machineconfigured for making polyethylene films. The machine may be configuredwith a feed hopper in fluid communication with an extruder in heatingcommunication with a heating device capable of heating a polyethylene inthe extruder to a temperature of up to 500° C. (e.g., 430° C.), andwherein the extruder is in fluid communication with a die having aninner diameter of 20.3 centimeters (8 inches) and a fixed die gap (e.g.,1.778 millimeter gap (70 mils)), a blow up ratio of 2.5:1, and a FrostLine Height (FLH) of 76±10 centimeters (30±4 inches) from the die. Step(a) may be done in the feed hopper. Steps (b) and (c) may be done in theextruder and at a temperature of 400° to 450° C. (e.g., 430° C.). Step(d) may be done in the die and after exiting the die. The machine mayhave capacity of a feed rate of (A) and (B), and production rate offilm, from 50 to 200 kilograms (kg) per hour, e.g., 91 kg (201 pounds)per hour at 430° C.

The polyethylene film is useful for making containers and wraps thathave at least one enhanced optical property. Examples of such containersare bags such as ice bags and grocery bags. Examples of such wraps arestretch films, meat wraps, and food wraps. The inventive blend andcomposition are also useful in a variety of non-film relatedapplications including in vehicle parts.

Advantageously we discovered that the polyolefin blend and polyolefincomposition have improved (i) at least one optical property relative tothat of constituent (A) alone and constituent (B) alone. In some aspectsthe at least one optical property, measured according to the ASTMmethods described herein using a film having a thickness of 0.0127millimeter (0.500 mil), is clarity (Zebedee), gloss (specular), or haze.In some aspects the enhancement of clarity (Zebedee) is from 3% to 35%,alternatively from 3% to 33%, alternatively from 10% to 32%, all whentested according to ASTM D1746-15, relative to expected clarity(Zebedee) at the same weight fraction concentration as derived from acomparative trend line for actual comparative clarity (Zebedee) valuesat 100% ZN-LLDPE and 100 wt % MCN-LLDPE. In some aspects the enhancementof gloss (specular) using a film having a thickness of 0.0127 millimeter(0.500 mil) is from 20% to 70%, alternatively from 25% to 65%,alternatively from 30% to 65%, all when tested according to ASTMD2457-13, relative to expected gloss (specular) values at the sameweight fraction concentration as derived from a comparative trend linefor actual comparative gloss (specular) values at 100% ZN-LLDPE and 100wt % MCN-LLDPE. In some aspects the enhancement of haze using a filmhaving a thickness of 0.0127 millimeter (0.500 mil) is from 10% to 70%,alternatively from 15% to 65%, alternatively from 20% to 60%, all whentested according to ASTM D1003-13, relative to expected haze values atthe same weight fraction concentration as derived from a comparativetrend line for actual comparative haze values at 100% ZN-LLDPE and 100wt % MCN-LLDPE. In some aspects the polyolefin blend is characterizedby, and a greater at least one optical property enhancement is obtainedwith, constituents (A) and (B) wherein the melt index (“I₂”, 190° C.,2.16 kg) of constituent (B) is within ±0.4 g/10 min., alternatively ±0.2g/10 min., alternatively ±0.1 g/10 min. of the melt index (“I₂”, 190°C., 2.16 kg) of constituent (A).

In some aspects the film of the polyolefin blend is characterized by acombination of composition, properties and characteristics that may giveextra enhancement of optical clarity-Zebedee, gloss, and/or haze. Insome such aspects the blend is composed of (A) having 1-butenecomonomeric units and a melt index value of 1.0±0.1 g/10 min. and (B)having a melt index value of 1.0±0.1 g/10 min. The melt index values are(“I₂”, 190° C., 2.16 kg) measured according to ASTM D1238-04. In somesuch embodiments, the film may have a thickness of 0.0127 mm (0.5 mil)and weight fractions of (A) and (B) in a range from 75 wt % (A)/25 wt %(B) to 25 wt % (A)/75 wt % (B). In other such aspects the film may havea thickness of 0.0381 mm (1.5 mil); and a weight fraction of (A) and (B)of 25 wt % (A)/75 wt % (B). In some such embodiments, the film may havea thickness of 0.0635 mm (2.5 mils) and a weight fraction of (A) and (B)of 25 wt % (A)/75 wt % (B) or 75 wt % (A)/25 wt % (B). In some suchembodiments, the film may have a thickness of 0.0127 to 0.635 mm (0.5mil to 2.5 mils) and weight fractions of (A) and (B) in a range from 75wt % (A)/25 wt % (B) to 25 wt % (A)/75 wt % (B).

In some such aspects the blend is composed of (A) having 1-butenecomonomeric units and a melt index value of 2.0±0.1 g/10 min. and (B)having a melt index value of 1.0±0.1 g/10 min. The melt index values are(“I₂”, 190° C., 2.16 kg) measured according to ASTM D1238-04. In somesuch embodiments, the film may have a thickness of 0.0127 to 0.0381 mm(0.5 to 1.5 mil) and weight fractions of (A) and (B) in a range from 75wt % (A)/25 wt % (B) to 25 wt % (A)/75 wt % (B). In other such aspectsthe film may have a thickness of 0.0381 to 0.0635 mm (1.5 to 2.5 mils);and a weight fraction of (A) and (B) of 25 wt % (A)/75 wt % (B).

In some such aspects the blend is composed of (A) having 1-hexenecomonomeric units and a melt index value of 1.0±0.1 g/10 min. and (B)having a melt index value of 1.0±0.1 g/10 min. The melt index values are(“I₂”, 190° C., 2.16 kg) measured according to ASTM D1238-04. In somesuch embodiments, the film may have a thickness of 0.0127 to 0.0635 mm(0.5 mil to 2.5 mils) and weight fractions of (A) and (B) in a rangefrom 75 wt % (A)/25 wt % (B) to 25 wt % (A)/75 wt % (B). In some suchembodiments, the film may have a thickness of 0.0127 to 0.0381 mm (0.5to 1.5 mil) and weight fractions of (A) and (B) in a range from 50 wt %(A)/50 wt % (B) to 25 wt % (A)/75 wt % (B). In some such embodiments,the film may have a thickness of 0.0127 mm (0.5 mil) and a weightfraction of (A) and (B) of 25 wt % (A)/75 wt % (B). In some suchembodiments, the film may have a thickness of 0.038 mm (1.5 mil) andweight fractions of (A) and (B) in a range from 75 wt % (A)/25 wt % (B)to 25 wt % (A)/75 wt % (B). In some such embodiments, the film may havea thickness of 0.0635 mm (2.5 mils) and weight fractions of (A) and (B)in a range from 50 wt % (A)/50 wt % (B) to 25 wt % (A)/75 wt % (B).

Olefin polymerization catalysts include Ziegler-Natta catalysts, Chromecatalysts, and molecular catalysts. Ziegler-Natta (Z-N) such asTiCl₄/MgCl₂ and Chrome catalysts such as a chromium oxide/silica gel areheterogeneous in that their catalytic sites are not derived from asingle molecular species. Heterogeneous catalysts produce polyolefinswith broad molecular weight distributions (MWD) and broad chemicalcomposition distributions (CCD). A molecular catalyst is homogeneous inthat it theoretically has a single catalytic site that is derived from aligand-metal complex molecule with defined ligands and structure. As aresult, molecular catalysts produce polyolefins with narrow CCD andnarrow MWD, approaching but in practice not reaching the theoreticallimit of Mw/Mn=2. Metallocenes are molecular catalysts that containunsubstituted cyclopentadienyl ligands (Cp). Post-metallocene arederivatives of metallocenes that contain one or more substituted CPligands, such as constrained geometry catalysts, or are non-sandwichcomplexes. Examples of post-metallocene catalysts are bis-phenylphenoxycatalysts, constrained geometry catalysts, imino-amido type catalysts,pyridyl-amide catalysts, imino-enamido catalysts, aminotroponiminatocatalysts, amidoquinoline catalysts, bis(phenoxy-imine) catalysts, andphosphinimide catalysts.

A compound includes all its isotopes and natural abundance andisotopically-enriched forms. The enriched forms may have medical oranti-counterfeiting uses.

In some aspects any compound, composition, formulation, mixture, orreaction product herein may be free of any one of the chemical elementsselected from the group consisting of: H, Li, Be, B, C, N, O, F, Na, Mg,Al, Si, P, S, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge,As, Se, Br, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb,Te, I, Cs, Ba, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi,lanthanoids, and actinoids; with the proviso that chemical elementsrequired by the compound, composition, formulation, mixture, or reactionproduct (e.g., C and H required by a polyolefin or C, H, and O requiredby an alcohol) are not excluded.

The following apply unless indicated otherwise. Alternatively precedes adistinct embodiment. AEIC means Association of Edison IlluminatingCompanies, Birmingham, Ala., USA. ASTM means the standards organization,ASTM International, West Conshohocken, Pa., USA. IEC means the standardsorganization, International Electrotechnical Commission, Geneva,Switzerland. ISO means the standards organization, InternationalOrganization for Standardization, Geneva, Switzerland. Any comparativeexample is used for illustration purposes only and shall not be priorart. Free of or lacks means a complete absence of; alternatively notdetectable. IUPAC is International Union of Pure and Applied Chemistry(IUPAC Secretariat, Research Triangle Park, N.C., USA). May confers apermitted choice, not an imperative. Operative means functionallycapable or effective. Optional(ly) means is absent (or excluded),alternatively is present (or included). PPM are weight based. Propertiesare measured using a standard test method and conditions for themeasuring (e.g., viscosity: 23° C. and 101.3 kPa). Ranges includeendpoints, subranges, and whole and/or fractional values subsumedtherein, except a range of integers does not include fractional values.Room temperature: 23° C.±1° C. Substantially free of a specific materialmeans 0 to 1 wt %, alternatively 0 to <0.1 wt %, alternatively 0 wt % ofthe material. Substituted when referring to a compound means having, inplace of hydrogen, one or more substituents, up to and including persubstitution.

Unless noted otherwise herein, use the following preparations forcharacterizations.

Blend and Film Preparation Methods 1. A blown-film-line machineconfigured for making polyethylene films with a feed hopper in fluidcommunication with an extruder in heating communication with a heatingdevice heated to a temperature of 430° C. The extruder is in fluidcommunication with a die having a fixed die gap of 1.778 millimeter (70mils), a blow up ratio of 2.5:1. The Frost Line Height (FLH) is 76±10centimeters (30±4 inches) from the die. The machine used a feed rate of(A) and (B), and production rate of film, of 91 kg (201 pounds) per hourat 430° C.

Density Test Method: measured according to ASTM D792-13, Standard TestMethods for Density and Specific Gravity (Relative Density) of Plasticsby Displacement, Method B (for testing solid plastics in liquids otherthan water, e.g., in liquid 2-propanol). Report results in units ofgrams per cubic centimeter (g/cm³).

Long Chain Branching (LCB) Test Method: calculate number of long chainbranches (LCB) per 1,000 carbon atoms of a test polymer using acorrelation developed by Janzen and Colby (J. Mol. Struct., 485/486,569-584 (1999)) between zero shear viscosity, η_(o), and M_(w). Theircorrelation is drawn as a reference line on a reference graph of η_(o)on the y-axis and M_(w) on the x-axis. Then a test polymer ischaracterized by (a) and (b): (a) using the Zero Shear ViscosityDetermination Method described later, measuring the test polymer'ssmall-strain (10%) oscillatory shear, and using a three parameterCarreau-Yasuda empirical model (“CY Model”) to determine values forη_(o) therefrom; and (b) using the Weight-Average Molecular Weight TestMethod described later, measuring the test polymer's M_(w). Plot theresults for the test polymer's η_(o) and M_(w) on the reference graph,and compare them to the reference line. Results for test polymers withzero (0) long chain branching per 1,000 carbon atoms will plot below theJanzen and Colby reference line, whereas results for test polymershaving long chain branching >0 per 1,000 carbon atoms will plot abovethe Janzen and Colby reference line. The CY Model is well-known from R.B. Bird, R. C. Armstrong, & O. Hasseger, Dynamics of Polymeric Liquids,Volume 1, Fluid Mechanics, 2^(nd) Edition, John Wiley & Sons, 1987; C.A. Hieber & H. H. Chiang, Rheol. Acta, 1989, 28: 321; and C. A. Hieber &H. H. Chiang, Polym. Eng. Sci., 1992, 32: 931.

Melt index (190° C., 2.16 kilograms (kg), “I₂”) Test Method: forethylene-based (co)polymer is measured according to ASTM D1238-04,Standard Test Method for Melt Flow Rates of Thermoplastics by ExtrusionPlatometer, using conditions of 190° C./2.16 kilograms (kg), formerlyknown as “Condition E” and also known as I₂. Report results in units ofgrams eluted per 10 minutes (g/10 min.) or the equivalent in decigramsper 1.0 minute (dg/1 min.). 10.0 dg=1.00 g. Melt index is inverselyproportional to the weight average molecular weight of the polyethylene,although the inverse proportionality is not linear. Thus, the higher themolecular weight, the lower the melt index.

Optical Clarity-Zebedee Test Method: ASTM D1746-15, Standard Test Methodfor Transparency of Plastic Sheeting. Measure clarity using a ZebedeeCL-100 Meter. Express clarity as the percentage ratio of the intensityof light with specimen and without specimen in the path of light.

Optical Gloss Test Method: ASTM D2457-13, Standard Test Method forSpecular Gloss of Plastic Films and Solid Plastics. Measure speculargloss using a glassometer at incident angles 20°, 45°, 60°, or 75°.Specular gloss is unitless.

Optical Haze Test Method: D1003-13, Standard Test Method for Haze andLuminous Transmittance of Transparent Plastics. Measure haze using ahazemeter. Express haze as percentage of luminous transmission which inpassing through the film deviates from an incident beam by forwardscattering.

Weight-Average Molecular Weight Test Method: determine M_(w), numberaverage molecular weight (M_(n)), and M_(w)/M_(n) using chromatogramsobtained on a High Temperature Gel Permeation Chromatography instrument(HTGPC, Polymer Laboratories). The HTGPC is equipped with transferlines, a differential refractive index detector (DRI), and three PolymerLaboratories PLgel 10 μm Mixed-B columns, all contained in an ovenmaintained at 160° C. Method uses a solvent composed of BHT-treated TCBat nominal flow rate of 1.0 milliliter per minute (mL/min.) and anominal injection volume of 300 microliters (μL). Prepare the solvent bydissolving 6 grams of butylated hydroxytoluene (BHT, antioxidant) in 4liters (L) of reagent grade 1,2,4-trichlorobenzene (TCB), and filteringthe resulting solution through a 0.1 micrometer (μm) Teflon filter togive the solvent. Degas the solvent with an inline degasser before itenters the HTGPC instrument. Calibrate the columns with a series ofmonodispersed polystyrene (PS) standards. Separately, prepare knownconcentrations of test polymer dissolved in solvent by heating knownamounts thereof in known volumes of solvent at 160° C. with continuousshaking for 2 hours to give solutions. (Measure all quantitiesgravimetrically.) Target solution concentrations, c, of test polymer offrom 0.5 to 2.0 milligrams polymer per milliliter solution (mg/mL), withlower concentrations, c, being used for higher molecular weightpolymers. Prior to running each sample, purge the DRI detector. Thenincrease flow rate in the apparatus to 1.0 mL/min/, and allow the DRIdetector to stabilize for 8 hours before injecting the first sample.Calculate M_(w) and M_(n) using universal calibration relationships withthe column calibrations. Calculate MW at each elution volume withfollowing equation:

${{\log\; M_{X}} = {\frac{\log\left( {K_{X}/K_{PS}} \right)}{a_{X} + 1} + {\frac{a_{PS} + 1}{a_{X} + 1}\log\; M_{PS}}}},$where subscript “X” stands for the test sample, subscript “PS” standsfor PS standards, a_(PS)=0.67, K_(PS)==0.000175, and a_(X) and K_(X) areobtained from published literature. For polyethylenes,a_(X)/K_(X)=0.695/0.000579. For polypropylenesa_(X)/K_(X)=0.705/0.0002288. At each point in the resultingchromatogram, calculate concentration, c, from a baseline-subtracted DRIsignal, I_(DRI), using the following equation: c=K_(DRI)I_(DRI)/(dn/dc),wherein K_(DRI) is a constant determined by calibrating the DRI, /indicates division, and dn/dc is the refractive index increment for thepolymer. For polyethylene, dn/dc=0.109. Calculate mass recovery ofpolymer from the ratio of the integrated area of the chromatogram ofconcentration chromatography over elution volume and the injection masswhich is equal to the pre-determined concentration multiplied byinjection loop volume. Report all molecular weights in grams per mole(g/mol) unless otherwise noted. Further details regarding methods ofdetermining Mw, Mn, MWD are described in US 2006/0173123 page 24-25,paragraphs [0334] to [0341].

Zero Shear Viscosity Determination Method: perform small-strain (10%)oscillatory shear measurements on polymer melts at 190° C. using anARES-G2 Advanced Rheometric Expansion System, from TA Instruments, withparallel-plate geometry to obtain complex viscosity |η*| versusfrequency (ω) data. Determine values for the three parameters—zero shearviscosity, η_(o), characteristic viscous relaxation time, τ_(η), and thebreadth parameter, a,—by curve fitting the obtained data using thefollowing CY Model:

${{{\eta^{*}(\omega)}} = \frac{\eta_{o}}{\left\lbrack {1 + \left( {\tau_{\eta}\omega} \right)^{\alpha}} \right\rbrack^{\frac{({1 - n})}{a}}}},$wherein |η*(ω)| is magnitude of complex viscosity, η_(o) is zero shearviscosity, τ_(η) is viscous relaxation time, a is the breadth parameter,n is power law index, and ω is angular frequency of oscillatory shear.

EXAMPLES

Constituent (A1): a ZN-LLDPE characterized by 1-butene comonomericcontent, a density of 0.918 g/cm³, and a melt index I₂ of 1.0 g/10 min.

Constituent (A2): a ZN-LLDPE characterized by 1-butene comonomericcontent, a density of 0.918 g/cm³, and a melt index I₂ of 2.0 g/10 min.

Constituent (A3): a ZN-LLDPE characterized by 1-hexene comonomericcontent, a density of 0.918 g/cm³, and a melt index I₂ of 1.0 g/10 min.

Constituent (B1): a MCN-LLDPE characterized by 1-hexene comonomericcontent, a density of 0.918 g/cm³, and a melt index I₂ of 1.0 g/10 min.

Comparative Example 1a (CE1a): a 0.0127 mm thick film of 100 wt % (A1).

Comparative Example 1b (CE1b): a 0.0127 mm thick film of 100 wt % (B1).

Comparative Example 2a (CE2a): a 0.0127 mm thick film of 100 wt % (A2).

Comparative Example 2b (CE2b): a 0.0127 mm thick film of 100 wt % (B1).

Comparative Example 3a (CE3a): a 0.0127 mm thick film of 100 wt % (A3).

Comparative Example 3b (CE3b): a 0.0127 mm thick film of 100 wt % (B1).

Inventive Example 1a (IE1a): a polyolefin blend and a 0.0127 mm thickfilm of 75 wt % (A1) and 25 wt % (B1).

Inventive Example 1b (IE1b): a polyolefin blend and a 0.0127 mm thickfilm of 50 wt % (A1) and 50 wt % (B1).

Inventive Example 1c (IE1c): a polyolefin blend and a 0.0127 mm thickfilm of 25 wt % (A1) and 75 wt % (B1).

Inventive Example 2a (IE2a): a polyolefin blend and a 0.0127 mm thickfilm of 75 wt % (A2) and 25 wt % (B1).

Inventive Example 2b (IE2b): a polyolefin blend and a 0.0127 mm thickfilm of 50 wt % (A2) and 50 wt % (B1).

Inventive Example 2c (IE2c): a polyolefin blend and a 0.0127 mm thickfilm of 25 wt % (A2) and 75 wt % (B1).

Inventive Example 3a (IE3a): a polyolefin blend and a 0.0127 mm thickfilm of 75 wt % (A3) and 25 wt % (B1).

Inventive Example 3b (IE3b): a polyolefin blend and a 0.0127 mm thickfilm of 50 wt % (A3) and 50 wt % (B1).

Inventive Example 3c (IE3c): a polyolefin blend and a 0.0127 mm thickfilm of 25 wt % (A3) and 75 wt % (B1).

The comparative and inventive films (0.0127 mm thickness, 0.5 mil) weretested for optical clarity-Zebedee according to Optical Clarity-ZebedeeTest Method. Compositions and test results are reported below in Tables1A to 3A.

TABLE 1A Compositions (1.0 MI 1-butene ZN-LLDPE/1.0 MI MCN-LLDPE) andClarity Test Results. (“0” means 0.00) Constituent (wt %) CE1a IE1a IE1bIE1c CE1b ZN-LLDPE (A1) 100 75 50 25 0 MCN-LLDPE (B1) 0 25 50 75 100Example Total 100.00 100.00 100.00 100.00 100.00 Actual Clarity-Zebedeetransmittance 63.0 76.5 72.8 65.2 60.5 (%) Comparative trend lineClarity-Zebedee 63.0 62.4 61.8 61.1 60.5 (%) Clarity Enhancement (%transmittance) 0 14.1 11.0 4.1 0 Clarity Enhancement (%) 0 22.6 17.8 6.70

TABLE 2A Compositions (2.0 MI 1-butene ZN-LLDPE/1.0 MI MCN-LLDPE) andClarity Test Results. (“0” means 0.00) Constituent (wt %) CE2a IE2a IE2bIE2c CE2b ZN-LLDPE (A2) 100 75 50 25 0 MCN-LLDPE (B1) 0 25 50 75 100Example Total 100.00 100.00 100.00 100.00 100.00 Actual Clarity-Zebedeetransmittance 55.0 63.6 75.6 61.1 60.5 (%) Comparative trend lineClarity-Zebedee 55.0 56.4 57.8 59.1 60.5 (%) Clarity Enhancement (%transmittance) 0 7.2 17.8 2.0 0 Clarity Enhancement (%) 0 12.8 30.8 3.40

TABLE 3A Compositions (1.0 MI 1-hexene ZN-LLDPE/1.0 MI MCN-LLDPE) andClarity Test Results. (“0” means 0.00) Constituent (wt %) CE3a IE3a IE3bIE3c CE3b ZN-LLDPE (A3) 100 75 50 25 0 MCN-LLDPE (B1) 0 25 50 75 100Example Total 100.00 100.00 100.00 100.00 100.00 Actual Clarity-Zebedeetransmittance 65.3 76.7 74.6 74.0 60.5 (%) Comparative trend lineClarity-Zebedee 65.3 64.1 62.9 61.7 60.5 (%) Clarity Enhancement (%transmittance) 0 12.6 11.7 12.3 0 Clarity Enhancement (%) 0 19.7 18.619.9 0

Clarity enhancement (% transmittance)=actual Clarity-Zebedeetransmittance (%)−% transmittance expected from comparative trend line,expressed in %, wherein “−” indicates subtraction. Clarity enhancement(%)=clarity enhancement (% transmittance)/(% transmittance expected fromcomparative trend line), expressed as a percentage, wherein “/”indicates division. The greater the increase in clarity-Zebedeetransmittance relative to the comparative trend line claritytransmittance, the greater the clarity enhancement.

The comparative and inventive films (0.0127 mm thickness, 0.5 mil) weretested for optical gloss according to Optical Gloss Test Method.Compositions and test results are reported below in Tables 1B to 3B.

TABLE 1B Compositions (1.0 MI 1-butene ZN-LLDPE/1.0 MI MCN-LLDPE) andGloss Test Results. (“0” means 0.00) Constituent (wt %) CE1a IE1a IE1bIE1c CE1b ZN-LLDPE (A1) 100 75 50 25 0 MCN-LLDPE (B1) 0 25 50 75 100Example Total 100.00 100.00 100.00 100.00 100.00 Actual Gloss, specular33.0 48.7 57.4 61.5 25.4 (at 45°) Comparative trend line 33.0 31.1 29.227.3 25.4 Gloss (at 45°) Gloss (at 45°) Enhancement 0 17.6 28.2 34.2 0Gloss (at 45°) 0 56.6 49.1 55.6 0 Enhancement (%)

TABLE 2B Compositions (2.0 MI 1-butene ZN-LLDPE/1.0 MI MCN-LLDPE) andGloss Test Results. (“0” means 0.00) Constituent (wt %) CE2a IE2a IE2bIE2c CE2b ZN-LLDPE (A2) 100 75 50 25 0 MCN-LLDPE (B1) 0 25 50 75 100Example Total 100.00 100.00 100.00 100.00 100.00 Actual Gloss, specular19.3 31.4 36.0 57.5 25.4 (at 45°) Comparative trend line 19.3 20.8 22.423.9 25.4 Gloss (at 45°) Gloss (at 45°) Enhancement 0 10.6 13.6 33.6 0Gloss (at 45°) 0 33.8 37.8 58.4 0 Enhancement (%)

TABLE 3B Compositions (1.0 MI 1-hexene ZN-LLDPE/1.0 MI MCN-LLDPE) andGloss Test Results. (“0” means 0.00) Constituent (wt %) CE3a IE3a IE3bIE3c CE3b ZN-LLDPE (A3) 100 75 50 25 0 MCN-LLDPE (B1) 0 25 50 75 100Example Total 100.00 100.00 100.00 100.00 100.00 Actual Gloss, specular40.6 36.0 42.2 47.8 25.4 (at 45°) Comparative trend line 40.6 36.8 33.029.2 25.4 Gloss (at 45°) Gloss (at 45°) 0 (0.8) 9.1 18.6 0 EnhancementGloss (at 45°) 0 (2.2) 27.6 63.7 0 Enhancement (%)

Gloss enhancement (% reflectance)=actual gloss reflectance (%)−%reflectance expected from comparative trend line, expressed in %,wherein “−” indicates subtraction. Gloss enhancement (%)=glossenhancement (% reflectance)/(% reflectance expected from comparativetrend line), expressed as a percentage, wherein “/” indicates division.The greater the increase in actual gloss reflectance relative to thecomparative trend line gloss reflectance, the greater the glossenhancement.

The comparative and inventive films (0.0127 mm thickness, 0.5 mil) weretested for optical haze according to Optical Haze Test Method.Compositions and test results are reported below in Tables 1C to 3C.

TABLE 1C Compositions (1.0 MI 1-butene ZN-LLDPE/1.0 MI MCN- LLDPE) andHaze Test Results. (“0” means 0.00) Constituent (wt %) CE1a IE1a IE1bIE1c CE1b ZN-LLDPE (A1) 100 75 50 25 0 MCN-LLDPE (B1) 0 25 50 75 100Example Total 100.00 100.00 100.00 100.00 100.00 Actual Haze (%) 17.511.1 8.4 7.6 20.1 Comparative trend 17.5 18.3 18.8 19.4 20.1 line Haze(%) Haze Enhancement 0 7.2 10.4 11.8 0 (% deviated) Haze Enhancement (%)0 39.3 55.3 60.8 0

TABLE 2C Compositions (2.0 MI 1-butene ZN-LLDPE/1.0 MI MCN- LLDPE) andHaze Test Results. (“0” means 0.00) Constituent (wt %) CE2a IE2a IE2bIE2c CE2b ZN-LLDPE (A2) 100 75 50 25 0 MCN-LLDPE (B1) 0 25 50 75 100Example Total 100.00 100.00 100.00 100.00 100.00 Actual Haze (%) 26.617.6 13.8 8.8 20.1 Comparative trend 26.6 25.0 23.3 21.7 20.1 line Haze(%) Haze Enhancement 0 7.4 9.5 12.9 0 (% deviated) Haze Enhancement 0 3041 59.4 0 (%)

TABLE 3C Compositions (1.0 MI 1-hexene ZN-LLDPE/1.0 MI MCN-LLDPE) andHaze Test Results. (“0” means 0.00) Constituent (wt %) CE3a IE3a IE3bIE3c CE3b ZN-LLDPE (A3) 100 75 50 25 0 MCN-LLDPE (B1) 0 25 50 75 100Example Total 100.00 100.00 100.00 100.00 100.00 Actual Haze (%) 12.621.2 13.0 12.1 20.1 Comparative trend 12.6 14.4 16.3 18.2 20.1 line Haze(%) Haze Enhancement 0 6.8 3.3 6.1 0 (% deviated) Haze Enhancement (%) 047 20 33 0

Haze enhancement (% deviated)=actual light deviated (%)−% light deviatedexpected from comparative trend line, expressed in %, wherein “−”indicates subtraction. Haze enhancement (%)=haze enhancement (%deviated)/(% light deviated expected from comparative trend line),expressed as a percentage, wherein “/” indicates division. The greaterthe decrease in actual amount light being deviated from 2.5° relative tothe comparative trend line amount light being deviated from 2.5°, thegreater the haze enhancement.

As shown by the data in Tables 1A to 3A, 1B to 3B, and 1C to 3C, theinventive polyethylene blends and films have weight fractionconcentrations of 75 wt % ZN-LLDPE/25 wt % MCN-LLDPE, 50 wt %ZN-LLDPE/50 wt % MCN-LLDPE, and 25 wt % ZN-LLDPE/75 wt % MCN-LLDPE, andenhanced (increased) optical clarity, enhanced (increased) lightreflectance or gloss, and enhanced (decreased) light deviated (haze)relative to the respective expected values at the same weight fractionconcentrations as derived from their respective comparative trend linesfor comparative such values at 100% ZN-LLDPE and 100 wt % MCN-LLDPE.

Optical clarity-Zebedee, gloss, and haze test results are also availablefor comparative that are identical to CE1a, CE1b, CE2a, CE2b, CE3a, andCE3b and inventive examples that are identical to IE1a to IE1c, IE2a toIE2c, and IE3a to IE3c except wherein thickness of the film is 0.0381 mm(1.5 mil) or 0.0635 mm (2.5 mils).

Incorporate by reference here the below claims as numbered aspectsexcept replace “claim” and “claims” by “aspect” or “aspects,”respectively.

The invention claimed is:
 1. A polyethylene blend comprising a uniformdispersion of constituents (A) and (B): (A) a Ziegler-Nattacatalyst-made linear low density polyethylene (ZN-LLDPE) and (B) ametallocene catalyst-made linear low density polyethylene (MCN-LLDPE);wherein the (A) ZN-LLDPE is from 24 to 76 weight percent (wt %) of thetotal weight of (A) and (B) and the (B) MCN-LLDPE is from 76 to 24 wt %of the total weight of (A) and (B); wherein by itself (A) isindependently characterized by each of properties (i) to (iii): (i) amelt index (“I₂”, 190° C., 2.16 kg) of 0.5 to 2.5 gram per 10 minutes(g/10 min.) measured according to ASTM D1238-04; (ii) a density from0.905 to 0.930 gram per cubic centimeter (g/cm³), measured according toASTM D792-13; and (iii) no detectable amount of long chain branching per1,000 carbon atoms (“LCB Index”), measured according to LCB Test Method;and wherein by itself (B) is independently characterized by each ofproperties (i) to (iii): (i) a melt index (“I₂”, 190° C., 2.16 kg) of0.5 to 2.5 g/10 min. measured according to ASTM D1238-04; (ii) a densityfrom 0.905 to 0.930 g/cm³, measured according to ASTM D792-13; and (iii)no detectable amount of long chain branching per 1,000 carbon atoms(“LCB Index”), measured according to LCB Test Method; and with theproviso that the density of constituent (B) is within ±0.001 g/cm³ ofthe density of constituent (A); wherein the (A) ZN-LLDPE is made bycopolymerizing ethylene and 1-butene in the presence of theZiegler-Natta catalyst and the (B) MCN-LLDPE is made by copolymerizingethylene and 1-hexene in the presence of the metallocene catalyst; andwherein the melt index of constituent (B) is within ±0.1 g/10 min. ofthe melt index of constituent (A).
 2. The polyethylene blend of claim 1,further characterized by one of limitations (i) to (ii): (i) each ofZN-LLDPE and MCN-LLDPE is independently characterized by a melt index of(“I₂”, 190° C., 2.16 kg) of 0.5 to 1.99 g/10 min.; and (ii) each of theZN-LLDPE and MCN-LLDPE is independently characterized by a density of0.918±0.003 g/cm³.
 3. The polyethylene blend of claim 1, when formed asa film having a thickness of 0.0127 millimeter (0.500 mil), is furthercharacterized by any one of limitations (i) to (vii): (i) an improvement(increase) in optical clarity (Zebedee), relative to optical clarity(Zebedee) of a film of (A) alone or (B) alone, of from 3% to 35%, whentested according to the Optical Clarity-Zebedee Test Method; (ii) animprovement (increase) in gloss of 15% to 65%, when tested according tothe Optical Gloss Test Method; or (iii) an improvement (decrease) inhaze of from 15% to 65%, when tested according to the Optical Haze TestMethod; or (iv) both (i) and (ii); (v) both (i) and (iii); (vi) both(ii) and (iii); or (vii) each of (i) to (iii).
 4. A method of making thepolyethylene blend of claim 1, the method comprising: (a) contactingdiscrete solid particles and/or a discrete melt of constituent (A) withdiscrete solid particles and/or a discrete melt of constituent (B) togive an initial mixture of (A) and (B); (b) heating any solid particlesof (A) and any solid particles of (B) in the initial mixture above theirmelting temperature to give a complete melt of constituents (A) and (B);(c) blending the complete melt to an even extent to give thepolyethylene blend as a uniform melt blend of constant composition of(A) and (B) throughout.
 5. The method of claim 4, further comprising (d)cooling the uniform melt blend to a temperature below its solidificationtemperature, thereby giving the polyethylene blend as a solid ofconstant composition of (A) and (B) throughout.
 6. A polyolefincomposition comprising the polyethylene blend of claim 1 and at leastone additive (constituent) (C) to (M): (C) a lubricant; (D) a polymerprocessing aid; (E) an antioxidant; (F) a metal deactivator; (G) anultraviolet light-promoted degradation inhibitor (“UV stabilizer”); (H)a slip agent; (I) a hindered amine stabilizer; (J) an antiblock agent;(K) a colorant; (L) an antifog agent; and (M) an antistatic agent; withthe proviso that the total amount of the at least one additive isfrom >0 to 5 wt % of the polyolefin composition and the polyethyleneblend is from <100 to 80 wt % of the polyolefin composition.
 7. A methodof making the polyolefin composition of claim 6, the method comprisingcontacting the polyethylene blend with the at least one additive (C) to(M) to give the polyolefin composition.
 8. A manufactured articlecomprising a shaped form of the polyethylene blend of claim
 1. 9. Apolyethylene film of the polyethylene blend of claim
 1. 10. A method ofmaking a polyethylene film, the method comprising blowing a melt of thepolyethylene blend of claim 1, thereby giving the polyethylene film.